A North Korean attempt to fire a missile from its east coast has failed, South Korean officials said, in what would be the latest in a string of unsuccessful ballistic missile tests conducted by Pyongyang.

South Korea's Joint Chiefs of Staff said in a statement that the North tried to launch an unidentified missile early in the morning from the town of Wonsan on Tuesday, but that it is likely to have failed.

Officials said later they were analysing the incident and gave no further details.

South Korea's official news agency, Yonhap, citing an unidentified government source, said the missile exploded at a mobile launchpad when the launch button was pressed.

Tension in Northeast Asia has been high since North Korea conducted a fourth nuclear test in January and followed that with a satellite launch and test launches of various missiles.

Japan put its military on alert on Monday for a possible North Korean ballistic missile launch.

"We have no reports of any damage in Japan. We are gathering and analysing data. The defense ministry is prepared to respond to any situation," Japanese Minister of Defence General Nakatani said.

"North Korea shows no sign of abandoning the development of nuclear missiles and so we will continue to work closely with the US and South Korea in response and maintain a close watch on North Korea."

Invasion rehearsal

The most recent launch follows Seoul's rejection of an offer from the North to talks.

All three missiles exploded in mid-air or crashed, according to South Korean defence officials.

The South's government believe the missile launches followed an order from the country's leader Kim Jong-un in March to conduct tests of a nuclear warhead and ballistic missiles capable of carrying such warheads.

That order was thought to be part of Pyongyang's reaction to annual South Korea-US military drills that it sees as a rehearsal for invasion.